Comtech EF Data SDM-2020 - Manual (Page 38)

SDM-2020 Satellite Modulator Revision 7
External Connections MN/SDM2020M.IOM
4-2
4.1.1 R
EMOTE
C
ONNECTOR AND
P
INOUT
(J1)
The remote control connection is a 9-pin female D connector located on the rear panel of
the modulator. Screw locks are provided for mechanical security of the mating connector.
The remote connector provides a means for issuing commands and determining the unit
status. This connector provides EIA-232, EIA-485 (2-wire), and EIA-485 (4-wire)
operation. The communications protocol and the control and status commands are
described in Appendix A.
Table 4-2. Remote Control Connector Pinout (J1)
Remote Control Connector (J1) Pinout
EIA-232C EIA-485 (2) EIA-485 (4)
Signal Type Signal Type Signal Type Pin #s
GND GND GND GND GND GND 1
RXD O N/A N/A N/A N/A 2
TXD I N/A N/A N/A N/A 3
N/A N/A +RX/+TX I/O +TX I 4
GND GND -RX/-TX I/O -TX I 5
DSR O N/A N/A N/A N/A 6
RTS I N/A N/A N/A N/A 7
CTS O +RX/+TX I/O +RX O 8
N/A N/A -RX/-TX I/O -RX O 9